The present invention relates to optical data transmission system for transmitting data by light waves through the atmosphere and, in particular, to such a system in which the changing atmospheric conditions are compensated for without the loss of data transmission.
There is a rapidly expanding need for data transmission and an infrastructure to accomplish same. While the use of fiber optics has increased the capacity and efficiency of data transmission, the expanding data transmission needs require continual additions to the fiber optics infrastructure at enormous expense and difficulty. While there have been experiments and attempts to augment the data transmission system by using light waves through the free-space of the atmosphere, the inevitable changes in atmospheric conditions have frustrated the accuracy and reliability of such atmospheric optical data transmission experiments and attempts. For example, dust, smoke, fog and rain can interfere with or block the transmission of light waves from one point to another by scattering and overall attenuation of the light beam, and other atmospheric conditions such as wind, heat waves and the like will create aberrations that are constantly changing whereby the light wavefront that is received is adversely effected to thereby impair the quality of the data transmission.
It is a principal object of the present invention to provide a novel free-space optical data transmission system that uses telescopes for transmitting and receiving the data-encoded light waves with adaptive optics systems for overcoming the aforementioned problems. A further object of this invention is to provide such an optical data transmission system with a wavefront curvature sensor and deformable curvature mirror type adaptive optics system for overcoming the atmospheric aberrations encountered in the data-encoded light wave transmitting and receiving system. A still further object of this invention is to provide such a free-space optical data transmission system using a pair of telescopes with each telescope both transmitting and receiving data-encoded light and, in addition, with means for distinguishing between the data-encoded light transmitted from and received by each of the telescopes. Another object of this invention is to provide such a free-space optical data transmission system using two telescopes spaced at a substantial distance from each other and with means for controlling the aiming of each telescope at the other telescope in response to sensing the intensity of the light received by each telescope from the other telescope.
Another principal object of this invention is to provide a bidirectional free-space optical data transmission system using a pair of transceivers spaced at a substantial distance from each other for both transmitting and receiving data-encoded light with each transceiver having an adaptive optics system for compensating for atmospheric aberrations. A more detailed object of this invention is to provide adaptive optics systems with each transceiver that compensate for aberrations in both the transmitted and the received data-encoded light. A further and important object of this invention is the use of light diffraction to isolate the operation of the pair of transceivers in the free-space optical data transmission system of this invention. Still another object of this invention is to use conjugation of the deformable mirror of the adaptive optics system to improve the performance of the optical data transmission system.
Other and more detailed objects and advantages of the present invention will appear to those skilled in the art from the following detailed description of the preferred embodiments and modifications in conjunction with the drawings.